1. Field of the Invention
The present invention relates to a multi-function pipe bending machine.
It is known that in many types of applications the formation along the same pipe of several bendings which are close to each other and oriented in opposite directions is often required, which means that it is for example necessary first to execute a bending to the right in a pipe length, and then a bending to the left in another length of the same pipe, the second bending being close to the first one.
In other cases bendings in succession are to be carried out in separate planes, for example in planes perpendicular to each other.
2. Prior Art
In the known art, such bendings are achieved through the sequential use of one pipe bending machine for carrying out the bending to the right for example, and a second pipe bending machine for executing the left bending.
In fact, if one would try to use the same machine for carrying out a bending in the opposite way with respect to the one provided by the machine, once the first bending has been executed he would be obliged to rotate the pipe. But this operation will be generally impossible when bendings are very close to each other because the pipe portion that has been already bent would interfere with the bending head. It is therefore absolutely necessary to remove the pipe from the first pipe bending machine, carry it to the second pipe bending machine and make all operations necessary for placement and mounting of the pipe to the second machine.
The operating steps briefly described above involve important downtime and production slowing down that give rise to an increase in the production costs when several bendings in opposite ways are necessary.
Attempts have been made to solve the above drawbacks by using bending heads equipped with a dual locking arrangement available at two positions rotated through 180.degree. from each other so that the bending to the right could be first carried out and subsequently the bending to the left. However these attempts have not been successful too, because in this solution important downtime periods during which the production operations are stopped are required for disassembling the head and carrying out its rotation.
In addition pipe bending machines of known type often do not allow the bending dies, that is the shaped components to which the pipe is forcedly made to adhere so that it may be suitably bent, to be easily replaced. In fact it is necessary to completely remove the pipe, replace the die and set the pipe in place again.
In addition, often a reduced range of different dies can be used on a single machine because the distance between the positioning axis of the pipe and the engagement pin of the die is fixed. As a consequence, for a given outer diameter of the pipe, there is only one bending radius in each machine according to which the same pipe can be bent.